Mobile access networks provide a facility for mobile nodes to communicate data to provide communications services such as, for example, voice communications or internet browsing whilst the mobile nodes roam through the access network. Moreover, mobile access networks, such as those operating in accordance with general packet radio systems, such as those specified by the third generation project partnership (3GPP) provide a facility for a mobile node to roam to another mobile access network operating in accordance with a 3GPP standard and to continue communicating data via the network as if the mobile node was attached to its home access network. Thus, the General Packet Radio System (GPRS) standard includes network elements which facilitate roaming of a mobile node to another network whilst allowing that mobile node to communicate data and to receive services as if that mobile node was attached to its own home network.
Increasingly, internet protocols for example those defined by the Internet Engineering Task Force (IETF) are used to provide communications services to mobile nodes. Thus, wireless access interface technologies such as Wimax and Wi-Fi provide a facility for a mobile node to communicate data via a wireless access gateway. Wireless access gateways therefore form the mobile node's initial access point of non 3GPP type networks. Whilst mobile internet protocols provide a facility for mobile nodes to acquire an internet address and to communicate data using an internet protocol when attached to a wireless access gateway, it would be desirable and usually essential for such mobile nodes to receive services associated with roaming which are usually more typically associated with a network operating in accordance with a general packet radio system, such as the 3GPP GPRS system.